In overcoming limitations or in achieving goals, practice is essential. This is the idea behind Krishna’s message to renounce all fruits of action as a way to perfecting the practice of yoga. By practicing the performance of work without expecting rewards, one can gain a lot in terms of control of the mind.

athaitad apy aśhakto ’si kartuṁ mad-yogam āśhritaḥ
sarva-karma-phala-tyāgaṁ tataḥ kuru yatātmavān

This can be roughly translated to:

If you are unable to do even this, in that case, take up Yoga for Me and renounce the results of all works by becoming controlled in mind.

– Bhagavad Gita 12.11